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Results for “ANTITHROMBIN”

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At least 991 records · Page 55Linked to original sources

PubMed1999

[Thrombosis induced by homocysteine does not depend on platelet aggregation or heparin cofactor's antithrombin activity].

OBJECTIVES: To partly elucidate the relationship between homocysteine(Hcy) and thrombosis, we observed Hcy's effects on platelet aggregation and antithrombin activity of heparin cofactor in vitro. METHODS: Platelet aggregation assay and chromogenic assay were used in this research. RESULTS: Homocysteine had no effects on platelet aggregation induced by ADP and thrombin or heparin cofactor's antithrombin activity in vitro (P > 0.05). CONCLUSION: There is no correlation between Hcy and the "ADP passway" of platelet aggregation. Thrombosis induced by Hcy does not depend on heparin cofactor's antithrombin activity either.

Adult↗

PubMed2002

Levels of F(1+2) prothrombin fragments and thrombin - antithrombin III (TAT) complexes in patients with dermatitis herpetiformis.

BACKGROUND: Dermatitis herpetiformis (DH) is a rare bullous disease of autoimmune etiology. It is an intestinocutaneous syndrome, in which vesicopapular cutaneous lesions are accompanied by gluten-dependent enteropathy. The diagnosis of DH is based on immunopathological investigation of unaffected skin fragment (granular IgA deposits present at the tops of dermal papillae and IgA - EmA present in the serum). MATERIAL/METHODS: The studied group consisted of 33 patients with dermatitis herpetiformis - 23 males and 10 females aged 22-78 (mean age 44.7). In all the patients, the following parameters of blood coagulation systems were determined in the plasma Levels of prothrombin fragments 1+2 (F(1+2)), levels of thrombin - antithrombin III (TAT) complexes, antithrombin III activity (AT III). RESULTS: In patients with dermatitis herpetiformis, the main level of F(1+2) fragments amounted to 9.08 nmol/l, as compared with 1.14 nmol/l in the control group (the difference statistically significant, p<0.0001). In DH patients, the levels of TAT complexes were over twice higher than among the controls and that difference also reached statistical significance (p<0.0001). Mean antithrombin III activity (AT III) in patients with DH reached 102.60% and was similar to that observed in the control group (104.68%). CONCLUSIONS: In patients with dermatitis herpetiformis, increased levels of F(1+2) prothrombin fragments and TAT complexes indicate enhanced in vivo thrombinogenesis. No statistically significant differences of F(1+2), TAT and AT III levels in DH patients related to their sex, age and duration of the disease were observed.

Adult↗

PubMed2002

Inhibition of thrombin generation in plasma by fibrin formation (Antithrombin I).

The adsorption of thrombin to fibrin during clotting defines "Antithrombin I" activity. We confirmed that thrombin generation in afibrinogenemic or in Reptilase defibrinated normal plasma was higher than in normal plasma. Repletion of these fibrinogen-deficient plasmas with fibrinogen 1 (gamma A/gamma A), whose fibrin has two "low affinity" non-substrate thrombin binding sites, resulted in moderately reduced thrombin generation by 29-37%. Repletion with fibrinogen 2 (gamma'/gamma A), which in addition to low affinity thrombin-binding sites in fibrin, has a "high affinity" non-substrate thrombin binding site in the carboxy-terminal region of its gamma' chain, was even more effective and reduced thrombin generation by 57-67%. Adding peptides that compete for thrombin binding to fibrin [S-Hir53-64 (hirugen) or gamma'414-427] caused a transient delay in the onset of otherwise robust thrombin generation, indicating that fibrin formation is necessary for full expression of Antithrombin I activity. Considered together, 1) the increased thrombin generation in afibrinogenemic or fibrinogen-depleted normal plasma that is mitigated by fibrinogen replacement; 2) evidence that prothrombin activation is increased in afibrinogenemia and normalized by fibrinogen replacement; 3) the severe thrombophilia that is associated with defective thrombin-binding in dysfibrinogenemias Naples I and New York I, and 4) the association of afibrinogenemia or hypofibrinogenemia with venous or arterial thromboembolism, indicate that Antithrombin I (fibrin) modulates thromboembolic potential by inhibiting thrombin generation in blood.

Afibrinogenemia↗

PubMed2002

Antithrombin 'DREUX' (Lys 114Glu): a variant with complete loss of heparin affinity.

Here we report the finding of a new natural antithrombin mutation that confirms the critical contribution of lysine 114 to the binding of the core heparin pentasaccharide, with the replacement of lysine 114 by glutamate causing a complete loss in affinity. The variant was identified in a father and son, the father having been investigated for an episode of cerebral ischaemia associated with hypercholesterolaemia. The variant forms SDS-stable complexes with activated factor X (fXa) and its thermal stability and rate of factor Xa inhibition in the absence of heparin are identical to those of normal antithrombin. Normal antithrombin binds to the high affinity heparin pentasaccharide with a Kd of 1nM, as detected by a 45% change in intrinsic fluorescence, resulting in a 230-fold increase in rate of factor Xa inhibition. However, no change in fluorescence was detected for the variant when titrated with heparin or the heparin pentasaccharide, nor was there detectable activation towards factor Xa, indicating a complete loss of heparin binding.

Animals↗

PubMedDate not supplied

[Antithrombin III level in patients with acute viral myocarditis].

The article focuses on the status of a natural anticoagulant antithrombin III in patients with acute viral myocarditis (AVM) and on modes of treatment thereof. It has been proved that there is a statistically significant correlation between a drop in concentration of antithrombin III and degree of severity of AVM. Convincing, statistically significant data have been obtained that antithrombin III gets increased in AVM patients undergoing complex therapy: in those patients running a mild course of the illness, a mild one presenting with elevated indices for homeostasis, a medium gravity course (diclofenac, heparin, thiotriasoline, quick-frozen plasma), and grave course as well (prednizolon, heparin, thiotriasoline, quick-frozen plasma), which fact can be taken account of in choosing a therapeutic regimen.

Acute Disease↗

PubMed1992

Antithrombin III activity and diabetes mellitus in the Ivory Coast population.

Antithrombin III activity was determined in 100 patients with diabetes mellitus (24 type I and 76 type II) residing on the Ivory Coast. Results showed a significant decrease of antithrombin III in the diabetic subjects as compared to a normal Ivorian population and an inverse correlation was found between antithrombin III activity and hyperglycemia.

Adolescent↗

PubMed1992

[Antithrombin ii in eclampsia: estimation of predictive value].

We have observed in our study that antithrombin III activity decreases very significatively in eclampsia (p < 0.0001). A level of 90% was defined as a threshold. All the rates which are under or equal to 90% have 78.3% as a positive predictive value and those over 90% have a 98.7% as a negative predictive value for the overcoming of eclampsia. We have concluded that the 90% antithrombin III activity represents the alarm level for over coming eclamptic crises. The determination of the antithrombin III activity must be systematically done in every hypertensive pregnancy with proteinuria.

Adult↗

PubMed1992

[Determination of antithrombin III in situ in the skin of patients with allergic arteriolitis].

The authors assessed antithrombin III in patients with allergic arteriolitis. Positive expression of antithrombin was assessed on endothelia, thrombi and infiltrate cells in approximately 2/3 of patients of the examined group (n = 23). The authors assume that expression of antithrombin III reflects inhibited hemocoagulation in the affected vessels as well as inhibition of leucocyte proteases in the above disease.

Antithrombin III↗

PubMed1992

Cell surface heparan sulfate proteoglycans from human vascular endothelial cells. Core protein characterization and antithrombin III binding properties.

Human aortic endothelial cells (HAEC) and human umbilical vein endothelial cells (HUVEC) were labeled with 35SO(4)2- for 48 h. The membrane-associated proteoglycans were solubilized from these monolayers with detergent and purified by ion-exchange chromatography on Mono Q, incorporation in liposomes, and gel filtration. The liposome-intercalated proteoglycans were 125I-iodinated and treated with heparitinase before SDS-polyacrylamide gel electrophoresis. Radio-labeled proteins with apparent molecular masses of 130, 60, 46, 35, and 30 kDa (HAEC) and 180, 130, 62, 43, and 35 kDa (HUVEC) were detected by autoradiography. Further characterization by affinity chromatography on immobilized monoclonal antibodies and by Northern blot analysis provided evidence for the expression of syndecan, glypican, and fibroglycan in human endothelial cells. Most of the heparan sulfate which accumulated in the subendothelial matrix was implanted on a 400-kDa core protein. This protein was immunologically related to perlecan and bound to fibronectin. Binding studies on immobilized antithrombin III suggested that all membrane-associated heparan sulfate proteoglycan forms had the capacity to bind to antithrombin III but that high affinity binding was more typical for glypican. Most of the proteoglycans isolated from the extracellular matrix also bound only with low affinity to antithrombin III. These results imply that glypican may specifically contribute to the antithrombotic properties of the vascular wall.

Antithrombin III↗

PubMed2003

Diagnostic value of D-dimer and antithrombin-III levels in predicting prosthetic heart valve thrombosis.

The aim of this prospective study was to investigate the diagnostic value of plasma D-dimer levels and antithrombin-III activity in predicting prosthetic valve thrombus. The study group comprised 97 consecutive patients with prosthetic heart valves (59 with mitral, 21 with aortic, and 17 with both mitral and aortic prostheses) and 35 healthy control subjects. Six patients presented with symptoms of obstruction; the remaining 91 were asymptomatic. Patients were evaluated by both transthoracic and transesophageal echocardiography. Asymptomatic nonobstructive thrombus was detected in 13 patients (13%), whereas obstructive thrombus was demonstrated in all symptomatic patients. Plasma antithrombin-III levels of patients with prosthetic valve thrombi were slightly lower than those of patients without thrombus and of the control group, but the difference was not statistically significant. However, significantly higher plasma D-dimer levels were observed in patients with prosthetic valve thrombi, compared with patients without thrombus and the control group (735 +/- 633 microg/L, 372 +/- 342 microg/L, and 228 +/- 219 microg/L, respectively). Valve thrombus, the prosthetic heart valve itself, and INR levels were identified as major determinants of plasma D-dimer levels. A plasma D-dimer level of >445 microg/L predicted the presence of a prosthetic valve thrombus with 57.8% sensitivity and 83.3% specificity (positive predictive value, 47.8%; negative predictive value, 87.8%). Current data suggest that increased plasma D-dimer levels can be clinically helpful in predicting the presence of prosthetic valve thrombus. Plasma antithrombin-III activity does not seem to have a diagnostic value in predicting prosthetic valve thrombi.

Adult↗

PubMed2004

[A new method for determination of antithrombin III and its diagnostic significance].

A new assay based on using an original chromogenic substrate (z-Ala-Ala-Arg-pNa) and designed for the determination of antithrombin III is described in the paper. It was used in examinations of patients with malignancy after surgery. The content of antithrombin III was detected to be lower in 12% of cases in 2 days after surgery. Additionally, patients with DIC, as complications after surgery, were examined to find out that the antithrombin III content was decreasing in them.

Adolescent↗

PubMed2005

[Gene diagnosis of antithrombin deficiency and factor VII deficiency].

Since 1996 we have performed gene diagnosis of hereditary antithrombin deficiency and factor VII deficiency. We studied twenty-three patients with antithrombin deficiency and identified eighteen distinct gene mutations including single nucleotide substitutions, small nucleotide deletions, a small nucleotide insertion, and whole gene deletions. In two patients, however, we couldn't find out any mutations. We studied three patients with factor VII deficiency and identified three missense mutations. Two patients were homozygous for the mutation, respectively. Unexpectedly one patient was heterozygous for a missense mutation in the EGF domain though her plasma level of factor VII was reduced to 7% of normal. These results revealed that the genetic backgrounds and molecular mechanisms of antithrombin deficiency and factor VII deficiency were highly heterogeneous.

Antithrombins↗

PubMed2006

[Standardization of coagulologic technique for antithrombin III estimation and its clinical application].

A standard assay procedure for estimating antithrombin III activity was derived from the Abildgaard technique as follows: 1) to decrease errors at the preanalytical stage, by using preliminarily defibrinated lyophilized plasma-calibrator and 2) to increase measurement accuracy, by using the concentration of a fibrinogen preparation and simplifying the analytical procedure. The estimation of plasma antithrombin activity in patients with pulmonary thromboembolism or sepsis points to the changes in antithrombin III activity.

Antithrombin III↗

PubMed1992

Abnormalities in von Willebrand factor and antithrombin III after cardiopulmonary bypass operations for congenital heart disease.

In patients with congenital heart disease two poorly understood postoperative complications are pulmonary hypertensive crises after repair of large atrioventricular or ventricular septal defects and right atrial and pulmonary thrombi after the Fontan operation. In this study we assessed whether cardiopulmonary bypass in these patients is associated with the release of agents that might induce platelet aggregation and vasoconstriction, such as biologically active von Willebrand factor and platelet-activating factor. In addition, we measured levels of anticoagulants such as antithrombin III and proteins C and S. Three groups of patients with congenital heart disease undergoing cardiopulmonary bypass were monitored through the perioperative period for secundum atrial septal defects, large atrioventricular or ventricular septal defects, and tricuspid atresia or univentricular heart (Fontan candidates). Control values were obtained from age-matched patients; patients requiring major noncardiac operations and those with cardiac disease not requiring cardiopulmonary bypass were also studied. After cardiopulmonary bypass in all three groups biologic activity of von Willebrand factor increased markedly in the immediate and early postoperative periods compared with preoperative values, whereas antithrombin III values were decreased. Platelet-activating factor was detected in only two patients with congenital heart disease, both in the early postoperative period. In contrast, patients who did not have cardiopulmonary bypass did not show these abnormalities. All measured parameters normalized at late follow-up (6 to 18 months after operation). Although cardiopulmonary bypass in these patients resulted in increased von Willebrand factor activity and decreased antithrombin III, changes that may predispose the patient to platelet aggregation and thrombus formation, absolute values in individual patients alone were not predictive of pulmonary hypertensive crises or detectable thrombi. This suggests that these hematologic abnormalities may contribute to but are not by themselves a cause of morbidity in the early postoperative period. Moreover, the increased von Willebrand factor biologic activity seen postoperatively in patients with congenital heart disease suggests that use of synthetic vasopressin may be ineffective and potentially detrimental.

Antithrombin III↗

PubMed1991

High frequency of antithrombin 3 and protein C deficiency following autologous bone marrow transplantation for lymphoma.

To investigate the possibility that a hypercoagulable state develops during autologous bone marrow transplantation (BMT), we measured levels of circulating natural anticoagulants and fibrinolytic proteins before and weekly during the hospital course of 18 patients undergoing autologous BMT for Hodgkin's and non-Hodgkin's lymphoma. Patients received either weekly (standard dose group) or daily (high dose group) vitamin K supplements with their total parenteral nutrition. By day 14 there had been a significant drop in protein C activity (mean of 95% of normal to 52%), protein C antigen (mean of 105% of normal to 70%), and antithrombin 3 activity (111% of normal to 83%), and an increase in fibrinogen (471-621 mg/dl) and tissue plasminogen activator (6.9-13.8 ng/ml). No changes were seen in free or total protein S, plasminogen activator inhibitor, prothrombin time or partial thromboplastin time. The decreases in protein C and antithrombin 3 persisted through day 28 after transplantation. The drop in protein C correlated strongly with decrease in serum albumin, suggesting impaired synthesis of these proteins by the liver. No differences were seen in any of these parameters between the standard and high dose groups. Deficiencies in anticoagulant proteins antithrombin 3 and protein C and a rise in fibrinogen without a concomitant improvement in fibrinolytic variables create a potentially hypercoagulable state which may contribute to the thrombotic complications of autologous BMT.

Adult↗

PubMed1991

Antithrombin III: a database of mutations.

Elucidation of the molecular defects responsible for antithrombin III deficiency is proceeding rapidly. In order that a record is kept of the new and duplicated mutations that are found, we have compiled a database that we plan to update annually. In this, the first report of the database, we list 6 antithrombin III locus sequence polymorphisms and 94 recorded mutations causing functional deficiency of the protein, 38 of which are novel. As is the case with mutations affecting other protein genes, most mutations of antithrombin III involve a CG to TG or CA change.

Antithrombin III↗

PubMed1990

[Disorders of thrombin interaction with the blood vessel wall and its inactivation by antithrombin III in experimental nephrotic syndrome].

In the experiments on white rats was conducted a comparative study of 125I-alpha-thrombin clearance and its inactivation by antithrombin III in animals of the control group and rats with the experimental nephrotic syndrome (Heymann nephritis). It was determined that alterations of thrombin binding to the vascular wall in the nephrotic syndrome induced the prolongation of the labelled enzyme half-life in the blood stream. The formation of 125I-alpha-thrombin complexes with antithrombin III was delayed in the nephrotic syndrome, that suggests the violation of mechanisms of thrombin inactivation by antithrombin III. The distortions of endothelium-mediated thrombin elimination and inactivation in the nephrotic syndrome resulted in the enzyme interaction with fibrinogen, which threatened organism by thrombosis.

Animals↗

PubMed1990

[Antithrombin III level in normal pregnancy and patients with pregnancy-induced hypertension].

During pregnancy an increase of antithrombin III can be observed. In hypertensive pregnant women this increase may be smaller. This fact may be a sign of hypertension induced disseminated intravascular coagulation and important for prognosis and therapy of pregnancy-induced hypertension. We carried out estimations of antithrombin III by double determinations using radial immundiffusion. Antithrombin III levels were lower in patient with pregnancy-induced hypertension.

Adult↗